It's high time to move to TLS, i. e. turn http://ftputil.sschwarzer.net into https://ftputil.sschwarzer.net.
http://ftputil.sschwarzer.net
https://ftputil.sschwarzer.net
See also
https://movingtohttps.com/
https://www.keycdn.com/blog/http-to-https/
https://hosting.1und1.de/digitalguide/websites/webseiten-erstellen/wie-stelle-ich-meine-seite-auf-ssl-und-https-um/
Done since a few months, so I close this ticket.